Photographic printing apparatus



Jan. 4, 1944. F, SHULL 2,338,671

PHOTOGRAPHIC PRINTING APPARATUS Filed Dec. 6-, 1941 F1 G 3 H FRANCIS M. SHULL.

INVENTOR M m %duldz" v 1 TTORNE YS Patented Jan. 4, 1944 PHOTOGRAPHIC PRINTING APPARATUS Francis M. Shull, Rochester, N. Y., assignor to Eastman Kodak Company, Rochester, N. Y., a corporation of New Jersey Application December 6,1941, Serial No. 421,913

1 Claim.

This invention relates to photographic printing apparatus and more particularly to an arrangement of the illuminating system in a printer so a single light source provides a beam oil light incident on the printing window at right angles thereto, and also provides a uniformly bright field for positioning and judging the recrd from a region of! the perpendicular axis of the record. a

In positioning and judging a record in a printing window prior to the printing operation, it is generally necessary for the operator to observe the record at an acute angle, while in printing it is always desirable, if not absolutely necessary," to illuminate the record perpendicularly. In accordance with the present invention, a single source of light is so arranged that both of these desirable features are secured.

The invention will be readily understood irom the following description when read in connection with the accompanying drawing in which:

Fig. 1 shows diagrammatically the preferred form of the invention;

Fig. 2 shows schematically the preferred form embodied in a projection printer; and

Fig. 3 shows a suitable wiring diagram for the printing lamp.

Referring to the drawing in which like reference characters designate like parts throughout, a printing window in adapted to support a recangle to the optic axis of the printer so that it is in substantial alignment of the printing window I0 and the eye ll of the observer. Ths Judging illumination coming from an acute angle is preferably rendered difiuse as by inserting in this judging beam a. diffusing medium such as an opal glass 18. It is to be noted that this diffusing medium '18 does not intercept the beam of light falling perpendicularly on the window Hi and, therefore, the printing may be done with specular light falling on the record It which is generally desirable, especially in projection printing.

The brightness or the lamp II for a printing operation is generally much greater than that desired for judging and, in accordance with the usual practice, the lamp II is preferably provided as shown in Fig. 3 with a series resistance 19 arranged to be shunted by a switch 20 during a printing cycle. As shown in Fig. 2, the switch 20 may be arranged near the paper holding panel I so as to be actuated when the paper holding platen 2i is lowered to initiate a printing cycle,

' Also, in accordance with the usual practice, I pre- 0rd to be printed is arranged to be illuminated by a lamp II by means of a mirror l2 arranged and positioned to direct light from the lamp ll perpendicularly onto the printing window ID, If, as shown, the printer is of the projection type, the record held in the window ill is imaged in a well-known manner by a suitable lens l3 onto a panel H for supporting the light-sensitive material, usually paper. In order that the illumination oi the printing window in may be more intense, suitable condenser lenses I5 are positioned between the lamp l i and the window 1.. When, as shown in Fig. 2, a record l6 to be printed is placed in the window III, the eye I! of the operator occupies a position oi! the optic axis of the printer and, in order for the record It to be positioned and judged correctly, it is desirable that the record It be illuminated with diffuse light and from such an angle as to be substantially aligned with the eye I! of the operator. In accordance with the present invention, this is accomplished by positioning the lamp II at an larly onto said window.

fer to provide a shielding member 22 for protecting sensitive material in position on the panel ll during judging and positioning of the record l8. This shielding member 22 may be suitably coupled, as shown, so as to be displaced to nonshielding position shown by broken lines when the platen 2| is moved to printing position.

From the above description of the invention as applied to a particular form of printer, it will be evident that it is adapted to many forms of printers and it will be obvious that the novel illuminating arrangement of the invention is not restricted to the specific arrangement illustrated for explaining the invention.

What I claim as new and desire to secure by Letters Patent of the United States is:

In a photographic printer having a window for supporting a photographic record normal to a printing axis, a light source positioned ofl! said axis for providing a record viewing'axis obliquely to the printing axis, a diffusing screen positioned between said light source and said window andon said viewing axis to provide diffused light along said viewing axis to permit the positioning and judging of the record at said window, and a mirror positioned on said printing axis to reflect specular printing light from said light source perpendicu- FRANCIS M. SHULL. 

